On 4/14/06, R.A. Hettinga <rah@shipwright.com> wrote:

... Say Hello to Voiceprinting Voice biometrics is poised to add more security to phone-based transactions in Europe.

we used a system like this for a retail directory assistance service called Infone. the caller could authenticate by pin, by voice, or both. the voice enrollment required the caller to say "hello, infone" three times or until a suitable voice print could be attained. then when the caller accessed the system they would simply say "hello, infone" and based on their incoming phone number the print was either accepted or rejected. the problem with these systems is that they can only select / identify an individual from a small group of possibilities and line quality / head colds can cause false negatives. for example, if more than 10 people were associated with an account the user had to enter a PIN to identify them, and then provide the "hello, infone" voice print for further authentication. it is also a non-trivial matter to tune the threshold for success/failure appropriately for a given set of users. this is all based on probabilities so you need to set the threshold high enough that the risk of false positives (impostors) is low enough to keep security/losses at acceptable limits while also preventing excessive numbers of false negatives that will annoy and aggravate your customers. still, the tech keeps getting (incrementally) better and it does provide an additional layer of defence. i'm not sure the currently excessive costs associated with this technology are worth the benefit though. (there are basically two companies who specialize in this stuff (they've bought up all the rest) and they charge a premium for these services and technologies :)